1. Field of the Invention
The invention relates to a method for providing software in radio-based cellular communication networks, and a communication network for implementing the method.
2. Description of the Related Art
In today's computer networks, a client-server structure is frequently used to provide new software, and this is generally also referred to as a software upgrade. This is characterized by a hierarchical structure, whereby the software is stored on a higher-order “server” computer, which, at the request of “client” computers connected to the server, provides the latter with the required software.
On the basis of this fundamental model, which is also referred to as a single-server architecture, further variants exist, in which e.g. a plurality of servers process requests from a multiplicity of lower-order clients (multi-server architecture). For temporary storage of the software, “proxy servers” can also be used, which are disposed in the hierarchy between the client and server. The software requested by a client is temporarily stored in the proxy server in this architecture, so that, when a new request is received from a different client, the software can be requested directly from the proxy server (which is normally located in physically closer proximity). This method is used, for example, on the Internet for temporary storage of frequently requested web pages.
In radio-based cellular communication networks, such as the existing GSM (Global System Mobile) network, or the planned UMTS (Universal Mobile Telecommunication System) network as a third-generation mobile network, software upgrades need to be carried out, e.g. an upgrade of a WAP (Wireless Application Protocol) browser. Here, the software can be provided by the manufacturer of a subscriber station, by a network operator or by an independent service provider.
If one of the aforementioned client-server architectures is used for the software upgrade, in which the software is stored centrally on servers in the mobile network and is transmitted from there to each individual subscriber station, this nevertheless produces unacceptable waiting times given the large number of subscriber stations. A model calculation can explain this:
A maximum of 6 minutes is to be taken to download new software. For this purpose, 100 servers are available, which are intended to distribute the software among 10 million subscriber stations. With sequential processing, the software download to all subscriber stations requires10,000,000*6 min./100 servers=10,000 hours>1 year.
Even with an increase in the number of servers to 1000, the software upgrade would still require around 1.5 months in the most favorable case. However, an increase in the number of servers incurs substantial costs and is therefore uneconomical.
Furthermore, in mobile communication networks, in contrast to a fixed network, no allocation of a subscriber station to a network connection is possible. Consequently, in the case of central provision of software by a higher-order server (e.g. in the GSM network by a base station), each subscriber station of the communication network must poll the relevant server at regular time intervals in order to determine whether new software is available for downloading. This generates an additional load.